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So as you can see in the video at the end of both songs I am having a issue with it cutting/shorting out. All i can think of is the tip31 transistors im using are overheating maybe? but what is really wierd is it shorts back to the speakers?? I have one transistor driving the blue leds and one driving the red leds. the red leds are being powered by a 9v supply and the blue is 15v( dont remember the MA but they both provide plenty. They are wall warts. When i  plug in the 9v power supply it makes a high pitch buzzing noise.... If anyone has any pinters i would appreciate it. Thinking of adding more transistors....

I cant figure out how to link it so just copy paste the link below into your browser...


and i'm following this diagram cause it does not have a switch like the others.



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8 years ago

Overheating could be an issue. You mentioned your using a wall wart for this? Is it a cheap adapter or a decent regulated 9V power supply? Have you tested the output of the adapter? Often the cheap ones have no power regulation in them. They are little more then a transformer and rectifier. So if there isn't a heavy enough load on the adapter the output on the 9V one could be as high as 15V.

The instructable only shows 4 LEDs and your pushing much more than that. Also there is a decided lack of current limiting resistors on the LEDs. This is also a major issue as the LEDS will continue to draw more and more current till something burns out. So the number of LEDs you have and any lack of resistors could be drawing way too much current through the transistor overheating it. So look up an LED calc and figure out the resistors you will need for the LEDs you have and the supplied voltage.


Answer 8 years ago

Sorry i guess i should've explained how i have it wired. I have 80 blue leds total wired in sections of 20 which are then wired in sections of 5 with current limiting resistors..they are only 1/4 watt instead of 1/2 watt like i wanted but i don't think that would matter being the leds only pull 100ma or so each set.

and the wall warts are just cheapo cell phone charger like ones. Im going to add more transistors and one regulated power supply and see if that fixes it.

What baffled me is that it shorts back into the speakers causing them to cut out...

my input is + & - directly soldered to the speakers to see a bass input and a..treble input. and so the volume knob on the speaker system can control the brightness and intensity of the lights and my phone can control total volume.